For a long time only two-dimensional images created by an X-ray unit were available to practitioners in order to make a diagnosis or prepare for a surgical operation in an osseous region.
For some years now, techniques for three-dimensional modeling of bone contours from images obtained by conventional medical imaging techniques, such as tomodensitometry, also known as scanning or MRI (magnetic resonance imaging) have been available to practitioners. However, in order to be implemented all of these known techniques require involvement on the part of the practitioner, to a greater or lesser extent, in particular in order to identify the bones to which the contours in each of the images correspond. This leads, fairly often, to an approximate assessment of the relative shape and position of the bones, which could lead to an inaccurate or erroneous diagnosis, or an unsuccessful orthopedic surgical operation with the aim, for example, of implanting a component of a prosthesis onto a bone.
It is noted that the rate of failure is slightly greater when the operation involves an articular region concealed by tissues and/or where access is limited. This is the case in particular with the shoulder joint, where surgery is made even trickier by the ligaments in the shoulder region.
There is thus a need for techniques which make it possible to assist or simulate the surgeon's movements, all the more so since the number of osseous or orthopedic surgical operations is expected to rise significantly in industrialized countries in the coming years.
Computer techniques which assist the surgical movement have certainly been proposed for surgery on the spinal column and for neurosurgery, these techniques being based on pre-operative X-ray images.
A drawback of these known techniques, called surgical navigation, is that they do not provide satisfactory results when applied to other types of surgery, in particular orthopedic surgery aimed at inserting a prosthetic implant.
A further drawback of these known surgical navigation techniques is that either the involvement of a support technician during the surgical operation is necessary, which is very costly, or the surgical team must undergo specific training in order to be able to carry out the tasks of the support technician for itself, which is difficult to implement in practice.